6. Perform pulmonary angiography using digital subtraction angiography (DSA). Cine angiography should be used only if the patient is not intubated and cannot hold breath for at least 5-8 seconds. The standard Grollman catheter, standard curved pigtail catheter, or another angiographic catheter may be used to achieve the desired position for pulmonary angiography. Perform a manual injection of 5-10 cc contrast with the catheter tip in the pulmonary main trunk to localize emboli in the right or left main pulmonary artery. Advance the catheter into the right or left pulmonary artery and perform selective angiography in the frontal view using 20 cc of contrast per 2 seconds via a power injector. Higher contrast volumes should not be used to avoid worsening of right heart failure. The second standard view (45 degree ipsilateral posterior oblique view) should be used only when biplane imaging is available. If both main pulmonary arteries are to be treated, selective angiography should be performed for both lungs separately.